After several requests, a developer makes his iPhone game visible to the color blind.

Color-blind players are not the main audience most developers think of when plotting their games.

They're not who Nitzan Wilnai of VGViews originally built for either when the Tetris-like games Tatomic ($4.99) and Tatomic Lite (free) first became available for iPhone and iPod Touch. Yet enough players requested a color-blind mode that Wilnai got to work.

The color-blind mode, found in the Options menu, swaps Tatomic's green-colored atoms with purple ones. In the free version, players must connect chains of same-hued atoms to clear the row, reminiscent of Tetris's iconic puzzle. The full version of Tatomic, however, gives you 30 levels and two additional modes--one in which you must create puzzle shapes, and another that will only clear an atomic chain when you attach a radioactive atom catalyst.

We tested both of Tatomic's color modes on one of CNET's own color-afflicted, who appreciated the difference right away, but still registered the blue atoms as white in both schemes.

It mattered little--he proclaimed the game "All the fun of the Large Hadron Collider, but without the risk."

Jessica Dolcourt reviews smartphones and cell phones, covers handset news, and pens the monthly column Smartphones Unlocked. A senior editor, she started at CNET in 2006 and spent four years reviewing mobile and desktop software before taking on devices.